• 제목/요약/키워드: Spin glass

검색결과 259건 처리시간 0.024초

PVK계 PLED에서 발광층의 두께 변화에 따른 광학 및 전도 특성 (Optical and Conduction Properties with the Thickness Variation of the Light-emitting Layer in PVK-Based PLED)

  • 장경욱;안희철;신은철;이은혜;윤희명;정동회;안준호;이원재;김태완
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.373-374
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    • 2007
  • We have fabricated polymer light-emitting diodes(PLED) in a structure of Glass/ITO/PVK/Al. Poly(N-vinylcabazole) (PVK) was deposited on the ITO glass with the spin coating method. PVK thickness is respectively 500nm, 300nm, 250nm and 200nm with the spin coter rotation speed of 2000, 3000, 4000 and 5000rpm. V-I, wavelength-transmittance, P-L and SEM of the fabricated devices were measured. From the result of P-L measurement, it was kept the optic properties of PVK raw powder when PVK thickness is 250nm. The knee-voltage of PVK PLED with 250nm thickness was 7V.

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SPIN GLASS BEHAVIOR AND ANTIFERROMAGNETIC EXCHANGE COUPLING IN LASER-DEPOSITED $Zn_{1-x}Co_xO$ THIN FILMS

  • Kim, Hyojin;Kim, Dojin;Ihm, Young-Eon;Kim, Jae-Hyun;Choo, Woong-Kil
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2002년도 동계연구발표회 논문개요집
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    • pp.94-95
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    • 2002
  • Recently, we have seen a rapid advance in the evolving field of spin electronics (or spintronics). In spintronics, some feasibilities of new electronic applications utilizing spin degree of freedom have been explored. Diluted magnetic semiconductors (DMSs) are premising materials for spintronics because they have both charge and spin degree of freedom in a single substance. DMSs are refereed to semiconductor alloys in which some atoms are randomly substituted for by magnetic atoms. (omitted)

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통계적 실험계획법을 이용한 SOG 평탄화 공정의 최적화 (Optimization of Spin-On-Glass Planarization Process Using Statistical Design of Experiments)

  • 임채영;박세근
    • 한국진공학회지
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    • 제1권1호
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    • pp.198-205
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    • 1992
  • 고집적 회로제작에 필수적인 평탄화 기술을 SOG를 이용하여 개발하였다. 1.5 micron double metal 기술의 공정변수들을 통계적 실험계획법을 적용하여 주요변수들을 찾 아내고 그들을 최적화하였다. 최적공적 조건은 SOG 도포 횟수는 2회, hot plate bake는 $300^{\circ}C$에서 충분히, 그리고 furnace curing은 $400^{\circ}C$ 이하에서 40분간 진행하는 것이었다.

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스핀-온-글라스 박막의 제조와 분석 (Preparation and Analysis of the SOG Films)

  • 임경란;최두진;박선진
    • 한국세라믹학회지
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    • 제29권11호
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    • pp.863-869
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    • 1992
  • A SOG(spin glass) solution with excellent wetting to Si wafers was prepared by acid-hydrolysis of Si(OEt)4 and Me2Si(OEt)2. The solution was spin coated on Si wafers, and effects of heat treatment of the film were characterized by TG/DTA, FTIR and Ellipsometry. Silica film was obtained by heat treatment at $600^{\circ}C$ within one hour, but heat treatment at 80$0^{\circ}C$ caused interfacial oxidation of the silicon substrate. Unexpectedly silica films with much better adhesion were obtained by curing at $600^{\circ}C$ for over 30 min. than those obtained by thermal oxidation.

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스핀 터널링 거대자기저항 효과를 이용한 랜덤 엑세스 메모리 (Random Access Memory utilizing Spin Tunneling Giant Magnetoresistance Effect)

  • 박승영;최연봉;조순철
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.950-953
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    • 1999
  • Spin tunneling giant magnetoresistance effect was studied to utilize in the application of random access memory. Ferromagnetic/Insulator/Ferromagnetic films were sputtered on glass substrates and perpendicular current was applied. Measurements of magneto- resistance of the junction showed 8.6% of MR ratio. Voltage output depends on the magnetization directions of the write line and read line, thus enabling the system to be used as a random access memory

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COLLINEARITY AND SPIN FREEZING

  • Vincze, I.;Kemeny, T.
    • 한국자기학회지
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    • 제5권5호
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    • pp.343-350
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    • 1995
  • An overview will be given on recent Mossbauer and magnetization investigation of the applied field dependence of the magnetic properties of typical systems without strong magnetic anisotropy and showing the absence of magnetic saturation in high fields (including iron-rich spin glass (amorphous $Fe_{93}Zr_{7}$, soft ferromagnets (amorphous $Fe_{88}Zr_{12}$, $Fe_{70}Ni_{20}Zr_{10}$ and $Fe_{88}B_{12}$) and pure Fe). The results emphasize that shape anisotropy due to surface irregularities causes misalignment between the magnetization and the applied field in the otherwise collinear magnetic structure.

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졸-겔법에 의한 강유전 BST 박막의 제조 및 특성(II) - 초음파의 효과 (Fabrication and Properties of ferroelectric BST thin films prepared by sol-gel method (II) - effect of ultrasound on properties of thin film)

  • 이진홍;박병옥;이승엽
    • 한국결정성장학회지
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    • 제11권6호
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    • pp.252-258
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    • 2001
  • ($Ba_{0.7}Sr_{0.3})TiO_3$박막을 ITO-coated glass 기판위에 spin-coating법으로 제조하였다. 제조된 용액을 초음파 bath 내에서 초음파 처리하여 균일화를 촉진시킨 후 박막을 제조하여 초음파 처리하지 않은 용액으로 제조한 박막과의 비교를 통하여 초음파 효과를 알아보았다. 용액의 초음파 처리로 박막의 결정화 온도를 다소 낮추었으며 박막의 표면이 보다 균일하고 치밀화되었고 거칠기도 8.4nm에서 5.6nm로 더 낮아졌다. 그리고 박막의 투광성 및 전기적 특성 또한 용액의 초음파 처리로 인하여 향상되었다.

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Magnetoresistance of Co/Cu/Co Spin Valve Sandwiches

  • Park, S. J.;Park, K. L.;Kim, M. Y.;j. R. Rhee;D. G. Hwang;Lee, S. S.;Lee, k. A.;Park, C. M.
    • Journal of Magnetics
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    • 제2권1호
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    • pp.7-11
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    • 1997
  • The dependence of magnetoresistance (MR) ratio on various variables like the thickness of the second Co layer, on the presence of cap layer, on deposition field (Hdep) and on annealing in Co/Cu/Co sandwiches was investigated. Spin-valve sandwiches were deposited on the corning glass by means of the 3-gun dcmagnetron sputtering at a 5 mTorr partial Ar pressure and room temperature. The deposition field was varied from 70 Oe to 720 Oe. The MR curve was measured by the four-terminal method with applied magnetic field up to 1000 Oe perpendicular to the direction of a current in the film plne. The MR ratio of glass/Fe(50${\AA}$)/Co(17${\AA}$)/Cu(24${\AA}$)/Cot(${\AA}$) fabricated by making 50 ${\AA}$ of Fe buffer layer has the maximum value of 8.2% when the thickness of the second Co layer was 17${\AA}$and the deposition field was 350 Oe. In the case of glass/Fe(50${\AA}$)/Co(17${\AA}$)/Cu(24${\AA}$)/Cot(${\AA}$) with Cu cap layer on top, the decrease in the MR ratio seemed to relate with the oxidation of the second Co layer. Samples prepared with deposition field showed greater MR ratios through the formation of more complete spin valve films. After annealing for 2 hours at 300$^{\circ}C$, the MR ratio of the samples prepared with deposition field decreased rapidly while the MR raito of the sample prepared without the field remained.

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열처리 온도에 따른 ITO/MEH-PPV/Al 구조의 유기 발광다이오드의 특성연구 (Properties of Organic Light Emitting Diode with ITO/MEH-PPV/Al Structure on Heating Temperatures)

  • 조중연;장호정
    • 마이크로전자및패키징학회지
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    • 제10권4호
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    • pp.35-38
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    • 2003
  • ITO/glass 기판 위에 발광물질로서 poly(2-methoxy-5-(2-ethylhexoxy)-1,4-phenylenevinylene (MEH-PPV)를 이용하여 스핀코팅법(spin coating)으로 Glass/ITOM/MEH-PPV/Al 구조를 가지는 고분자 유기 발광 다이오드를 제작하였다. MEH-PPV 박막형성시 열처리온도에 따른 다이오드의 전기적, 광학적 특성을 조사하였다. 열처리 온도를 $65^{\circ}C$에서 $170^{\circ}C$로 증가함에 따라 유기 발광다이오드의 발광휘도는 10V 인가전압에서 630 cd/$\m^2$에서 280 cd/$\m^2$로 크게 감소하였다. 또한 $65^{\circ}C$에서 열처리한 시료의 경우 약 2 lm/W의 최대 발광효율을 나타내었다. 이러한 결과는 높은 온도에서 열처리시 MEH-PPV 유기 형광층과 전극간의 상호반응에 의한 계면 거칠기의 증가와 새로운 절연층의 형성 등과 관련이 있는것으로 판단된다.

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